HS-SPME-GC-MS Analysis of onion (Allium cepa L.) and shallot (Allium ascalonicum L.)

The volatile organic compounds of onion and shallot were determined via HS-SPME-GC -MS.The main components were dipropyldisulphide and allylpropyldisulphide.Thiopropanal S-oxide were detected only in onion volatiles.In shallot is interesting the presence of 2-methyl-2-pentenal, a compound with an intense fruity aroma, that can characterize the different aroma between onion and shallot.The SPME-GC-MS analysis of shallot after absorption on the SPME fiber at 50°C showed the presence of new compounds, whose structures have been discussed.